(19)
(11) EP 1 343 190 A3

(12) EUROPEAN PATENT APPLICATION

(88) Date of publication A3:
20.04.2005 Bulletin 2005/16

(43) Date of publication A2:
10.09.2003 Bulletin 2003/37

(21) Application number: 03004095.0

(22) Date of filing: 25.02.2003
(51) International Patent Classification (IPC)7: H01H 59/00, H01P 1/12
(84) Designated Contracting States:
AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HU IE IT LI LU MC NL PT SE SI SK TR
Designated Extension States:
AL LT LV MK RO

(30) Priority: 08.03.2002 JP 2002063141
11.03.2002 JP 2002065540

(71) Applicant: Murata Manufacturing Co., Ltd.
Nagaokakyo-shi Kyoto-fu 617-8555 (JP)

(72) Inventors:
  • Fujii, Yasutaka
    Nagaokakyo-shi, Kyoto-fu 617-8555 (JP)
  • Kobayashi, Shinji
    Nagaokakyo-shi, Kyoto-fu 617-8555 (JP)
  • Kawai, Hiroshi
    Nagaokakyo-shi, Kyoto-fu 617-8555 (JP)
  • Takemura, Koji
    Nagaokakyo-shi, Kyoto-fu 617-8555 (JP)
  • Konaka, Yoshihiro
    Nagaokakyo-shi, Kyoto-fu 617-8555 (JP)
  • Kobayashi, Masato
    Nagaokakyo-shi, Kyoto-fu 617-8555 (JP)

(74) Representative: Schoppe, Fritz, Dipl.-Ing. 
Patentanwälte Schoppe, Zimmermann, Stöckeler & Zinkler P.O. Box 246
82043 Pullach bei München
82043 Pullach bei München (DE)

   


(54) Variable capacitance element


(57) A coplaner line 3 or signal conduction and a movable body 4 displacing vertically through a supporting bar 6 are provided on a substrate 2. A movable electrode 7 is provided between a driving electrode 8 and driving electrodes 12 and 14. Voltage is applied between the movable electrodes 7 and 8, the movable electrode 7 is pressed against the line 3 through a dielectric film 10. Thus, high frequency signals conducting through the line 3 are shut off. When voltage is applied between the electrodes 12 and 14, the movable electrode 7 and the dielectric film 10 are moved apart from the line 3. Thus, high frequency signals can be conducted through the line 3. Therefore, malfunction of the variable capacitance type switch 1 can be prevented even when the movable electrode 7 is unexpectedly displaced by vibration, impact and so on.









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